The generalization of vicarious extinction effects

Behav. Rn.

&

‘Therapy.1970.

Vol. 8, pp. 323 to 330. Pergsmon

Press.

Rimed

in England

THE GENERALIZATION OF VICARIOUS EXTINCTION EFFECTS” EDWARD B. BLANCHARD University of Georgia, Athens, Georgia, U.S.A.

(Received I3 March 1970) Summary-Post-treatment tests for increases in snake approach behavior, shown by formerly snake phobic adults who had been treated with a participant modeling procedure or one of its derivatives, revealed a significantly greater degree of generalization of increases for Ss in a purely modeling condition than was found for those who had participated directly. Extinction data collected during the treatment process revealed similar reductions from direct and vicarious extinction. A very strong relationship was found between vicarious extinction in observers and the degree of generalization of snake approach behavior increases.

As BANDURA (1969) has clearly pointed out, one of the major problems facing behavior therapists, and ail other mental health professionals, is that of ensuring the generalization of treatment effects, such as the extinction of a phobia, from the actual treatment situation to the remainder of the patient’s environment. Despite the great practical significance of this problem, it has received little attention. A notable exception has been the studies by Bandura and his associates who have routinely tested for generalization of extinction of fear by presenting subjects with a novel example of the feared object at the post-treatment assessment (e.g. Bandura, Grusec and Menlove, 1967; Bandura, Blanchard and Ritter, 1969). Results on the generalization of changes in phobic behavior achieved through a participant modeling approach are presented in this paper. A purely observational procedure, which represents one component of the participant modeiing technique, apparently offers particular promise with regard to the critical area of generalization of changes. The mechanisms involved in successful generalization, found in the modeling approach, were studied also. METHOD The data for this paper were collected as part of a larger study (Blanchard, 1969) the principal results of which are reported elsewhere (Blanchard, 1970, in press). From the following overview of the experimental situation for the larger study, one can see where the present study fits. * This paper is based in part on a dissertation submitted to the Graduate Division of Stanford University in partial fulfilment of the requirements for the degree of Doctor of Philosophy. This study was supported in part by Research Grant M-5162 to Albert Bandura from the National Institute of Mental Health and by a National Institute of Mental Health Pre-Doctoral Research Fellowship, l-Fl-MH-38, 502-01, to the author.

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Snake phobic subjects were individually matched on initial approach behavior in groups of four and randomly assigned to conditions. In each quartet one subject, the participant, (P), was treated by the standard participant modeling procedure (Bandura et a/., 1969) which included the benefits of modeling, verbal information and direct contact with the snake. Two other subjects simultaneously observed the treatment from adjacent rooms through one-way mirrors: One of these‘observers (OL) listened via earphones to the verbal interchange of E and P, thus having exposure to two of the three variables, modeling and information; the second observer (0) received only the benefits of modeling. The fourth subject (C), who received none of the constituent elements, participated only in the assessment procedures. Subjects Forty-eight subjects were recruited through an advertisement in local newspapers and from introductory psychology classes at Stanford University (15 Ss). Six males and 42 females, ranging in age from 14 to 50 years with a median age of 22, were included. Approach Behavior Test The Approach Behavior Test (ABT) consisted of a graded series of 29 items involving increasingly more intimate contacts with a live snake. A double blind procedure was used in which a second E, who had no other part in the experiment, administered the ABT prior to initial assignment to condition and again at the conclusion of the treatment. The items are described in more detail elsewhere (Bandura et al., 1969). The terminal approach task consisted of the subject’s picking up the snake from its glass cage with her bare hands, holding it close to her face for a few seconds, and then allowing it to crawl around freely on her lap while her arms were at her side. The snake used in the pre-treatment assessment and during the treatment phase was a brown and white striped king snake approximately four feet in length. At the posttreatment assessment, both the experimental snake and a generalization snake, a red and brown splotched corn snake, four feet long, were used in counterbalanced order. Prior testing (Bandura et al., 1969) had shown them to be equally fearsome in that they elicited the same degree of approach behavior from a different set of Ss. Experimental

treatment

The three part participant modeling procedure described in more detail in Blanchard (1970, in press) was used for P. -After observing close snake-interaction behavior repeatedly modeled by the experimenter, subjects were aided through demonstration and joint participation to perform progressively more threatening approach responses. In addition they were provided with reassuring information regarding characteristics of snakes. Measurement

of fear arousal during treatment

The procedure for assessing fear arousal during the treatment process consisted of having the Ss make fear ratings for 11 different approach responses, representing increaswas ingly more threatening interactions with the snake. The actual rating procedure conducted as follows: after each time P performed one of the selected tasks, E directly asked her to rate the intensity of the fear she experienced while performing the approach behavior. During the actual performance of the task, E, by means of a remotely controlled

THE GENERALIZATION OF VICARIOUS EXTINCTION ?%FECTS

325

light operated by a foot pedal switch, signalled the observers to rate their own level of fear arousal. The rating of any given task was repeated as many times as P performed it. For each of the approach responses selected for ratin g, P was required to perform behavior at least four times. RESULTS A comparison of pre-trea~ent ABT scores showed no significant differences between the groups (F < 1.O>. The post-treatment test (Table 1) shows an advantage for the treatment

TABLE 1. APPROACHBEHAVIORTESTRESULTSFORDFFERENTTREATMENT CONDITIONS

Percentage*of Ss showingterminal approach behavior on Approach Behavior Test Treatment condition Experimentalsnake

Generalizationsnake

P

83

25

OL

33

8

0

50

42

C

0

0

Results

Participant

modeling

Symbolic modeling

from Bandura, Nanchard and Ritter (1969) 92

50

33

33

* All percentages are based on n= 12 per condition.

combining modeling and direct extinction; surprisingly, however, this advantage does not hold up when one considers the generalization of fear extinction. The data from measurement of fear arousal during the treatment process (Fig. 1) help explain this finding by showing equivalent degrees of extinction for direct or vicarious experience. Further analyses (Tables 2 and 3) show a strong relationship between the aspect of modeling called vicarious extinction of fear arousal and the degree of generalization of extinction; this is confirmed by subject self-report on the post-treatment questionnaire (Table 4). A more detailed consideration of the results follow: Approach behavior

A stringent test of the efficacy of the treatments is the percentage of subjects in each treatment condition who achieve terminal approach behavior with the experimental snake and the degree to which this generalized. In Table I are presented these percentages, and for comparison purposest the results for two relevant treatment groups from the Bandura et al. (1969) study.

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I-

t-e---e

-0

B. BLANCHARD

Modeling Modeling Modeling

+ InformatIon + Information

t

Contact

,I-

lntermediote

First Exposurer

L4Sl

to Arousing

Stimuli

FIG. 1. Mean fear arousal level during treatment

experienced by each group as a function of repeated exposures to threatening stimuli.

TABLE 2. RELATIONSHIP OF VICARIOUSFEAR EXTINCTION TO TERMINAL APPROACHBEHAVIOR*

Degree of fear extinction Post-treatment

approach behavior Complete

Partial

Terminal behavior

6

4

No terminal behavior

2

10

* Total n=22 for this table since in one triad P never performed any of the tasks selected for rating, and consequently the two observers never had any exposure to vicarious extinction processes.

TABLE 3. RELATIONSHIPOFMCARIOUS FEAREXTINCTIONTO GENERALlZATIONOFTERMlNALAPPROACHBEHAVlOR

Degree of fear extinction Degree of generalization Complete

Partial

Complete

6

0

Incomplete

0

4

THE GE?lERALIZXTION -i-ABLE

4.

RELATItZ

HELPFUL?iESS

OF VICARIOUS

TO OBSERVERS

EXTINCTION

OF COMPONENTS

327

EFFECTS

IN THE TREATMENT

PROCEDURE

Mean ratings Successful observer

Factor a. b.

Seeing P handle effects

without

Significance level of difference

adverse 2.0

1.14

0.01

1.8

1.14

0.05

1.7

1.00

0.05

Learning correct way to handle snake from watching E and P

1.6

1.21

ns

Deciding if P could handle snake, 0 herself could

1.6

0.86

0.02

Graduation

1.6

1.57

ns

1.5

1.38

RS

0.6

0.50

us

Knowledge that P was fearful as 0 at beginning of experiment

c* Seeing E handle effects d.

snake

Unsuccessful observer

Information comments

snake

without

adverse

of treatment procedure on snakes gamed from

Having to pay attention make ratings

E’s

to own feelings to

The data in Table I reveaIed that a higher per cent of Ss in the direct participation condition achieved terminal behavior than those of the two observer conditions. However, when terminal behavior was achieved, it tended to be significantly more generalized (p = 0.05 by Fisher’s Exact Probability Test on actual frequency data) for Ss receiving only modeling than those receiving either modeling with information and/or modeling combined with information and direct contact.

Extinction offear arousal during treatment In Fig. 1 are plotted the curves for rate of fear extinction as a function of repeated exposure to modeling displays. Each point on the graph represents the mean fear arousal score of 11 Ss for all 1I different approach tasks for which Ss were required to rate their emotional reactions, or the mean of 121 different ratings. There were no scores for one triad of Ss because the participant of that group never performed the first task that was selected for rating. Moreover, in a second triad P did not complete aIf I1 tasks to be rated, so that the means for the Iast four tasks were based on 10 Ss. Fear arousal ratings were plotted for the first time P performed a given activity, the last time she performed the same response, and for two intermediate points, after approximately l/3 and 2/3 of the total exposures. An analysis of variance was performed on these data: Treatments (F=46.6; p
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B. BLANCHARD

significantly different from each other (p ~0.01) in order of decreasing arousal - OL> P > 0 at all points, except P was lower than OL at the 0.05 level for the initial ratings; and P and 0 were not significantly different at the final rating. Moreover, there was a significant decrement (p ~0.05) in arousal for all three groups between the adjacent points. Relationship of vicarious fear extinction to increase in approach behavior In Table 2 are presented the number of Ss in the two observer groups who are able to perform terminal approach behavior with the experimental snake as a function of whether or not they achieved complete vicarious extinction of fear, defined as a final rating of zero for six or more of the eleven rated tasks. The obtained positive relationship between vicarious extinction and performance of terminal approach behavior was significant at the 0.05 level by Fisher’s Test. The above relationship is further confirmed by the generalization data. In Table 3 are presented the number of Ss in the observer groups who showed terminal approach behavior toward both snakes as a function of complete vicarious extinction of fear arousal. The frequency data shown in Table 3 is highly significant (p=O.OOS) by Fisher’s Test. These two sets of data thus reveal a strong relationship between vicarious extinction of fear arousal and complete elimination of avoidance behavior. Factors aiding elimination of phobic behavior Subjects in both observer groups rated eight factors on their relative helpfulness in overcoming their fear of snakes. In Table 4 the eight factors are listed in order of decreasing importance for the observers. The differences between the average ratings of the successful observers, who achieved terminal performances, and those of unsuccessful observers are presented in the table. These data were subjected to an analysis of variance in which both Groups (F=7.03; p
DISCUSSION Most studies conducted within a behavior therapy framework regularly include an objective measure of change in behavior. Results of the present study call attention to the

THE GENERALIZATION

OF VICARIOUS

EXTISCTION

EFFECTS

329

importance of also including tests for generalization of change in evaluating treatments approaches. For example, in this study the participant modeling procedure, which can be viewed as chiefly a combination of modeling and direct extinction (Blanchard, 1970, in press), was the most effective in increasing approach behavior to the target example of the feared object. However, when the degree of generalization of increased approach behavior was measured, the purely observational procedure proved more powerful. Bandura (1968, 1969) has speculated that the process involved in the modeling approaches is one of vicarious extinction of conditioned emotional arousal in which conditioned fear is vicariously aroused and progressively extinguished through the repeated observation of approach responses, considered to be hazardous, which result in no adverse consequences to the model. The detailed fear arousal measures indicated just such a process : The observers displayed a progressive reduction in fear arousal similar to that of the direct participants with succeeding exposures to the fear provoking stimuli. As might be expected, the participants were initially more fearful than their matched observers, but the former dispIayed a sharper rate of extinction than the observers, finishing at a similar point. This non-response, or central process, extinction of avoidance behavior is analogous to the results reported by Black (1958), who extinguished avoidance responses of the skeletally immobilized dogs through repeated exposure to aversive stimufi. The questionnaire results, while not conclusive, also support the idea that the observed changes in approach behavior were due to the vicarious extinction process, rather than to other facets of the experiment such as the reassuring info~ation about snakes or the graduation of the task. The reassuring verbal information seemed to provide an arousing effect only for which there was no effective counter-measure. This was clearly shown in detailed fear arousal measures. Subjects who both observed and received information were more fearfully aroused throughout the procedure than their matched partners who merely observed the same model performances. Research is planned to explore this paradoxical finding further. The most important finding of this study is probably that the more thoroughly emotional arousal was extinguished vicariously, the greater and more generalized was the change in the instrumental behavior. Perhaps the reason for this effect is that, since no peripheral motor responses are involved in vicarious extinction, the central processes involved have more generalized effects than are found when specific motor acts are invoIved in the extinction. The success of the vicarious extinction procedures, coupled with similar results from Bandura et al. (1969) utilizing a radically different form of modeling, a filmed display of strangers rather than a live display of acquaintances, points to the need to examine and utilize central processes within the behavior therapy rubric, particularly to enhance generalization effects. REFERENCES approaches to the modification of phobic disorders. In C&z Found&an Symposium: The RoIe ofLearning in Psychofherapy. Churchill, London. BANDURA A. (1969) Principles ofBehavior Modification. Halt, Rinehart & Winston, New York. BANDLRA A., BLANCHARDE. B. and RITIXR B. J. (1969) The relative efficacy of desensitization and modeling treatment approaches for inducing affective, behavioral and attitudinal changes. 2. persorr. SOC.Psychol. 13, 173-199. BAMXJRA A., GRUSECJ. E. and MENLovE F. L. (1967) Vicarious extinction of avoidance behavior. J.persort. sot. Psychol. 5, 16-23. BANDURAA. (1968) Modeling

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BLACK A. H. (1958) The extinction

B. BLANCHARD

of avoidance responses under curare.

J. conq. physiol. Psychol. 51,

519-525. E. B. (1969) The relative contributions of modeling, info~ational influences, and physical contact in the extinction of phobic behavior. Unpublished doctoral dissertation, Stanford University, Stanford, California. BLANCHARD E. B. (1970) The relative contributions of modeling, informational influences, and physical contact in the extinction of phobic behavior. J. ubnornz. Psycho!. (in press). WINER B. J. (1962) Statistical Principles in Exper~~e~tai Design. McGraw-Hill, New York. BLANCHARD